Diacoustic :: Diacoustic (a.) Pertaining to the science or doctrine of refracted sounds.
Diacoustics :: Diacoustics (n.) That branch of natural philosophy which treats of the properties of sound as affected by passing through different mediums; -- called also diaphonics. See the Note under Acoustics.
Subdiaconate :: Subderivative (n.) A word derived from a derivative, and not directly from the root; as, friendliness is a subderivative, being derived from friendly, which is in turn a derivative from friend..
Subdiaconate :: Subdiaconate (a.) Of or pertaining to a subdeacon, or to the office or rank of a subdeacon..